Merge 4309af1d37 into cba88226f4

btcutil/address.go

@@ -52,6 +52,10 @@ var (
 	// than assuming or defaulting to one or the other, this error is
 	// returned and the caller must decide how to decode the address.
 	ErrAddressCollision = errors.New("address collision")
+
+	// ErrIncorrect describes an error where an address could be decoded, but
+	// it was not for the expected network.
+	ErrIncorrectNet = errors.New("address is for incorrect net")
 )
 
 // encodeAddress returns a human-readable payment address given a ripemd160 hash
@@ -223,6 +227,26 @@ func DecodeAddress(addr string, defaultNet *chaincfg.Params) (Address, error) {
 	}
 }
 
+// DecodeAddressForNet decodes the string encoding of an address and returns
+// the Address if addr is a valid encoding for a known address type and the
+// given network.
+//
+// This method differs from DecodeAddress in that DecodeAddress tolerates
+// differing networks, in case the network parameter isn't needed to decode
+// the address.
+func DecodeAddressForNet(addr string, net *chaincfg.Params) (Address, error) {
+	decoded, err := DecodeAddress(addr, net)
+	if err != nil {
+		return nil, err
+	}
+
+	if !decoded.IsForNet(net) {
+		return nil, ErrIncorrectNet
+	}
+
+	return decoded, nil
+}
+
 // decodeSegWitAddress parses a bech32 encoded segwit address string and
 // returns the witness version and witness program byte representation.
 func decodeSegWitAddress(address string) (byte, []byte, error) {

btcutil/address_test.go

@@ -879,6 +879,67 @@ func TestAddresses(t *testing.T) {
 			continue
 		}
 
+		// Ensure addresses are only valid for their given network
+		// The cases where test.addr and test.encoded are different are
+		// pay-to-pubkey, and these are valid for all nets.
+		if test.valid && test.addr == test.encoded {
+			_, err := btcutil.DecodeAddressForNet(test.addr, test.net)
+			if err != nil {
+				t.Errorf("%s: invalid for expected net: %s", test.name, err)
+			}
+
+			nets := []chaincfg.Params{
+				chaincfg.MainNetParams,
+				chaincfg.TestNet3Params,
+				chaincfg.RegressionNetParams,
+				chaincfg.SimNetParams,
+				chaincfg.SigNetParams,
+				customParams,
+			}
+
+			// verify we can't decode for other nets
+			for _, net := range nets {
+				if net.Net == test.net.Net {
+					continue
+				}
+
+				decoded, err := btcutil.DecodeAddressForNet(test.addr, &net)
+				if err != nil {
+					continue
+				}
+				// signet bech32 addresses have the same HRP prefix as
+				// testnet. Skip those. We verify this with an interface
+				// check instead of concrete types, as there's multiple
+				// concrete types that implement Segwit addresses.
+				type bech32 interface {
+					Hrp() string
+				}
+				if _, ok := decoded.(bech32); ok &&
+					net.Net == chaincfg.SigNetParams.Net {
+					continue
+				}
+
+				// testnet3, signet and regtest shares the same pubkey hash
+				// prefixes. Skip those.
+				if _, ok := decoded.(*btcutil.AddressPubKeyHash); ok &&
+					(net.Net == chaincfg.SigNetParams.Net ||
+						net.Net == chaincfg.RegressionNetParams.Net) {
+					continue
+				}
+
+				// testnet3, signet and regtest shares the same script hash
+				// prefixes. Skip those.
+				if _, ok := decoded.(*btcutil.AddressScriptHash); ok &&
+					(net.Net == chaincfg.SigNetParams.Net ||
+						net.Net == chaincfg.RegressionNetParams.Net) {
+					continue
+				}
+
+				t.Errorf("%s: was able to decode address %s for incorrect net %s: 0x%02x",
+					test.name, decoded, net.Name, int(net.Net))
+			}
+		}
+
 		// Valid test, compare address created with f against expected result.
 		addr, err := test.f()
 		if err != nil {